Gun barrels are required to withstand high internal pressures. In addition, military application requires severe (e.g. rapid sequential burst) firing schedules which subject them to high temperatures which cause wear and erosion, substantially shortening their useful life. While wear will occur throughout the length of the barrel, the most severe problem occurs at the origin of rifling, i.e., at the chamber end where the highest temperatures and pressures exist. As the projectile moves toward the muzzle, the increased volume within the gun barrel results in lowering of propellant gas pressure so that barrel strength need not be as great at the muzzle as at the breech. Previous attempts to improve barrel life have included use of high cost specialized materials such as CG27 for the entire barrel. Liners or inserts are also used at the chamber end to increase barrel life. Such inserts are normally made of stellite, an alloy containing a large percentage of cobalt which is both an expensive and scarce critical material available only from foreign sources. While such inserts minimize the requirements for costly material, a small insert of such material may typically cost as much or more than the remaining material in the barrel mass. While they do substantially improve life, the selection of the barrel and insert materials always results in a compromise, since the requirements for material properties vary along the length of the bore, as well as being dependent on other factors such as caliber, propellant type, and firing rates encountered. As a practical matter, the mentioned factors cannot be varied to improve barrel service life, because the existing U.S. combat weapon inventory represents a massive and irreversible commitment of resources. To change caliber, propellant type or firing rate would alter those operational design limits upon which the entire weapon is based, which would require replacement of entire stockpiles instead of one single weapon component. Accordingly, the present invention is intended as a solution to problems in presently available gun barrels and their composition as described hereinbefore, by avoiding any change in gun functions or operational limits such as would require design changes in the basic weapon and massive replacement of existing U.S. weapon inventories.